This library adds a safe(r) interface on top of libjpeg-turbo and MozJPEG for reading and writing well-compressed JPEG images.
The interface is still being developed, so it has rough edges and may change.
In particular, error handling is weird due to libjpeg's peculiar design. Error handling can't use Result, but needs to depend on Rust's resume_unwind (a panic, basically) to signal any errors in libjpeg. It's necessary to wrap all uses of this library in catch_unwind.
In crates compiled with panic=abort setting, any JPEG error will abort the process.
std::panic::catch_unwind(|| {
let d = mozjpeg::Decompress::with_markers(mozjpeg::ALL_MARKERS)
.from_path("tests/test.jpg")?;
d.width(); // FYI
d.height();
d.color_space() == mozjpeg::ColorSpace::JCS_YCbCr;
for marker in d.markers() {}
// rgb() enables conversiono
let image = d.rgb()?;
image.width();
image.height();
image.color_space() == mozjpeg::ColorSpace::JCS_RGB;
let pixels = image.read_scanlines()?;
assert!(image.finish_decompress());
Ok(())
})?;std::panic::catch_unwind(|| {
let mut comp = mozjpeg::Compress::new(mozjpeg::ColorSpace::JCS_RGB);
comp.set_size(width, height);
comp.set_mem_dest();
comp.start_compress();
// replace with your image data
let pixels = vec![0; width * height * 3];
assert!(comp.write_scanlines(&pixels[..]));
comp.finish_compress();
let jpeg_bytes = comp.data_to_vec()?;
// write to file, etc.
Ok(())
})?;